长白落叶松PAL基因SNPs筛选及木质素含量关联分析

The Screening of SNPs in Gene PAL in Larix olgensis and Correlation Analysis with Lignin Content

为探究长白落叶松PAL基因的多态性以及与木质素含量之间的关系,本研究以吉林省四平市林木种子园中120个长白落叶松无性系为材料,测量各无性系的木质素含量并对不同无性系进行PAL基因克隆及分析,结果显示:不同无性系间木质素含量差异达极显著水平,表明无性系间木质素含量差异较大,对其进行遗传改良意义重大;对3个落叶松无性系不同部位进行PAL基因克隆,发现不同组织均有该基因表达;对120个无性系PAL基因进行克隆、测序及分析结果共筛选出11个SNP位点,均位于基因编码区,其中有7个属于转换类型位点,4个属颠换类型位点;不同无性系间遗传距离范围是0.000~0.035 cM之间;关联分析结果发现4个与木质素含量显著相关的SNP位点(SNP116, SNP922, SNP1150和SNP1186),4个位点均是非同义突变位点,且除SNP116外,纯合突变型无性系木质素含量更高。本研究结果可以为长白落叶松分子遗传改良提供基础,也可以为其他树种分子育种提供借鉴。

In order to study the polymorphism of gene PAL and its relationship with lignin content, this study took120 clones of Larix olgensis in forest seed orchard(Siping city of Jilin Province) as material. The lignin content were measured and the polymorphism in gene PAL was identified using DNA sequencing. The results showed that the lignin content had extremely significant difference among different clones which indicated that there was a great difference in lignin content among clones, so it was of great significance to carry out genetic improvement..Cloning of PAL gene from different organization of 3 L. gmelinii clones showed that the gene was expressed in all the text tissues. After cloning and sequencing of PAL gene form 120 L. olgensis clones, 11 SNP sites(including 7 transformational sites and 4 transversion sites) which were located in the coding region were selected. The range of genetic distance between different clones was 0.000~0.035 cM. The results of correlation analysis showed that four SNP loci(SNP116, SNP922, SNP1150 and SNP1186) were significantly related to lignin content. 4 SNPs were all nonsynonymous mutation sites and the lignin content of mutational clones was higher except SNP 116. The results of this study could provide the basis for molecular genetic improvement of L. olgensis, and it could also provide reference for molecular breeding of other tree species.